numpoly.where

numpoly.where(condition: ArrayLike, *args: numpoly.typing.PolyLike) → ndpoly

Return elements chosen from x or y depending on condition.

Note

When only condition is provided, this function is a shorthand for np.asarray(condition).nonzero(). Using nonzero directly should be preferred, as it behaves correctly for subclasses. The rest of this documentation covers only the case where all three arguments a re provided.

Args:

condition:

Where True, yield x, otherwise yield y.

x:

Values from which to choose. x, y and condition need to be broadcastable to some shape.

Return:

An array with elements from x where condition is True, and elements from y elsewhere.

Example:

>>> poly = numpoly.variable()*numpy.arange(4)
>>> poly
polynomial([0, q0, 2*q0, 3*q0])
>>> numpoly.where([1, 0, 1, 0], 7, 2*poly)
polynomial([7, 2*q0, 7, 6*q0])
>>> numpoly.where(poly, 2*poly, 4)
polynomial([4, 2*q0, 4*q0, 6*q0])
>>> numpoly.where(poly)
(array([1, 2, 3]),)